1. Field of the Invention
2. Description of the Prior Art
The invention is based on a fuel supply system for internal combustion engines, having a fuel tank and a fuel reservoir disposed therein, having means for filling the fuel reservoir with fuel from the tank, and having a fuel line that hydraulically connects the fuel reservoir to the internal combustion engine.
Fuel supply systems of this kind are known. The purpose of the fuel reservoir is to assure that the fuel line, which extends into the fuel supply system, aspirates fuel and not air for as long as possible. This is particularly important when the tank is near empty and/or when the vehicle is subject to powerful lateral accelerations so that the contents of the fuel tank are pushed to the side. This effect is achieved in that the fuel reservoir has a relatively small base and a height that corresponds approximately to the height of the fuel tank so that only a relatively small volume of fuel is required to fill the fuel reservoir. This fuel volume is supplied to the fuel reservoir by one or more fuel pumps, which aspirate fuel from the low point(s) of the fuel tank. In order to reduce costs, an electric fuel pump is usually provided inside the fuel reservoir and drives one or more jet pumps disposed in the low point(s) of the fuel tank; the jet pumps supply fuel into the fuel reservoir. This arrangement obviates the need to provide an electric fuel pump in every low point of the fuel tank, which would be expensive and prone to malfunction.
In many internal combustion engines, the fuel is supplied by means of a fuel line, which aspirates in a fuel supply system. The fuel is delivered by a fuel-supply pump directly coupled to the engine. This means that at low speeds of the engine, the fuel-supply pump only has a very low delivery capacity. As a result, the fuel-supply pump aspirates little or no fuel from the fuel supply system, which has a disadvantageous effect on the starting behavior of the engine. This also places heavy loads on the starter and starter battery. This operating behavior is particularly problematic when the fuel tank has been run out of gas, when the vehicle is first filled with fuel at the manufacturer, or at low outside temperatures when the performance of the starter battery is reduced.
The object of the invention is to produce a fuel supply system for internal combustion engines, which improves the starting behavior of the engine even under unfavorable conditions and consequently contributes to reducing the strain on the starter battery and the starter.
This object is attained according to the invention by means of a fuel supply system for internal combustion engines having a fuel tank and a fuel reservoir disposed therein, having means for filling the fuel reservoir with fuel from the fuel tank, and having a fuel line providing a fluid connection between the fuel reservoir and the engine, where the means for filling the fuel reservoir at least sometimes supply fuel into the fuel line.